How to change asp:DropDownList extended background color ? CSS class

Question

Here the class and the example

    <asp:DropDownList ID="dropDownListZenithYesNo" 
    CssClass="dropDownBox" runat="server"></asp:DropDownList>

And here the CSS class of that dropdownlist

.dropDownBox
{
    font-size: 13px;
    color: #3b3b3b;
    padding: 5px;
    background: -moz-linear-gradient(
    top,
    #f0f0f0 0%,
    #d6d6d6);
    background: -webkit-gradient(
    linear, left top, left bottom, 
    from(#f0f0f0),
    to(#d6d6d6));
    -moz-border-radius: 3px;
    -webkit-border-radius: 3px;
    border-radius: 3px;
    border: 1px solid #999999;
    -moz-box-shadow: 0px 1px 2px rgba(000,000,000,0.5), inset 0px 1px 0px rgba(255,255,255,1);
    -webkit-box-shadow: 0px 1px 2px rgba(000,000,000,0.5), inset 0px 1px 0px rgba(255,255,255,1); 
    box-shadow: 0px 1px 2px rgba(000,000,000,0.5), inset 0px 1px 0px rgba(255,255,255,1);
     text-shadow: 0px 1px 0px rgba(255,255,255,1), 0px 1px 0px rgba(255,255,255,0);
}

And here how it looks nice when you not click to see elements

And this is how very bad it looks when you click to see elements

Testing with windows 7 firefox latest version

CSS CSS3 HTML dropdown list color style

Answer 1

Add the following css below your css

.dropDownBox option
    {
        font-size: 13px;
        color: #3b3b3b;
        padding: 5px;
        background: -moz-linear-gradient(
top,
#f0f0f0 0%,
#d6d6d6);
        background: -webkit-gradient(
linear, left top, left bottom, 
from(#f0f0f0),
to(#d6d6d6));
        -moz-border-radius: 3px;
        -webkit-border-radius: 3px;
        border-radius: 3px;
        border: 1px solid #999999;
        -moz-box-shadow: 0px 1px 2px rgba(000,000,000,0.5), inset 0px 1px 0px rgba(255,255,255,1);
        -webkit-box-shadow: 0px 1px 2px rgba(000,000,000,0.5), inset 0px 1px 0px rgba(255,255,255,1);
        box-shadow: 0px 1px 2px rgba(000,000,000,0.5), inset 0px 1px 0px rgba(255,255,255,1);
        text-shadow: 0px 1px 0px rgba(255,255,255,1), 0px 1px 0px rgba(255,255,255,0);
    }

But test your page in multiple browsers because it may have different results. Infact i have different results.

Answer 2

You must be inheriting from a default style. I would suggest specifying the color for your options:

.dropDownBox option{
    font-size:1.2em;
    background-color:#FF0 !important;
    display:block;
}

Here is the fiddle